In the prior art there are many instances where a plurality of regulating elements are utilized for providing a regulated voltage from an unregulated source of voltage. Generally, a plurality of regulating elements are connected in a series relationship with respect to one another in order to handle a relatively high unregulated input voltage. For example, in a series regulated power supply having two regulating elements connected in series with each other, the individual regulating elements, when placed in an on condition, will be subjected to approximately one-half of the applied unregulated input voltage. The problem with such an arrangement is that under certain conditions one of the two regulating elements may not turn on at exactly the same time as the other of the two regulating elements. Under these conditions, the regulating element which turns on second will be subjected to the full value of the applied unregulated input voltage. Unless the regulating elements are highly over-designed, it is very likely that the regulating element subjected to the full input voltage will burn out.
The present invention provides a technique whereby a plurality of regulating elements may be utilized in a power supply wherein circuitry is provided to ensure that all of the regulating elements turn on and turn off simultaneously. In addition, the present invention also provides a means for increasing the efficiency of the type of power supply described. These results are accomplished in a way which is not complex or costly to implement.